Adaptor for exhaust manifold

ABSTRACT

An adaptor plate by which oversize exhaust pipes may be connected to the exhaust ports of a cylinder head of an internal combustion engine. The oversize exhaust pipes are welded to a header flange which has exhaust holes therein adapted to be aligned with the exhaust ports of the head of said engine by means of additional threaded screw holes formed in said adaptor plate at greater radial distances from the exhaust passages therein and said adaptor plate also having countersunk holes therein adjacent the peripheries of the exhaust passages therein for reception of bevel headed screws which are threaded into the conventional threaded holes adjacent opposite sides of the exhaust ports of the cylinder head to secure the adaptor plate to said head.

United States Patent [191 Stahl 1 Feb. 20, 1973 [54] ADAPTOR FOR EXHAUST MANIFOLD Jere F. Stahl, 1420 E. Philadelphia Street, York, Pa. 17403 [22] Filed: Dec. 2,1971

[21] Appl. No.: 204,026

[76] Inventor:

[56] References Cited UNITED STATES PATENTS 2,026,848 1/1936 Ruber; ..60/321 3,366,145 1/1968 Lohn ,...285/177 3,470,690 10/1969 Thompson ..60/313 Primary ExaminerDouglas Hart Attorney-C. Hercus Just 1571 ABSTRACT An adaptor plate by which oversize exhaust pipes may be connected to the exhaust ports of a cylinder head of an internal combustion engine. The oversize exhaust pipes are welded to a header flange which has exhaust holes therein adapted to be aligned with the exhaust ports of the head of said engine by means of additional threaded screw holes formed in said adaptor plate at greater radial distances from the exhaust passages therein and said adaptor plate also having countersunk holes therein adjacent the peripheries of the exhaust passagestherein for reception of bevel headed screws which are threaded into the conventional threaded holes adjacent opposite sides of the exhaust ports of the cylinder head to secure the adaptor plate to said head.

5 Claims, 6 Drawing Figures PATENTEUFEBZO ms INVENTOR.

J5EE F .STAHL TTOPNE) ADAPTOR FOR EXHAUST MANIFOLD BACKGROUND OF THE INVENTION The cylinder heads of internal combustion engines are provided with exhaust ports therein along one side thereof. Pairs of threaded holes are provided in said head respectively adjacent opposite sides of said exhaust ports for the connection of an exhaust manifold to said head, the manifold having inlet ports therein adapted to be aligned with the exhaust ports in the head. The threaded holes by which the manifold is secured to said head normally are quite close to the peripheries of the exhaust ports in the head.

The use of oversized exhaust pipes on racing cars and so-called hot rod cars is quite popular at present. It is not uncommon for such oversized exhaust pipes to be of the order of between one-fourth inch and one-half inch larger in diameter than the exhaust ports in the head of the engine. Therefore, when it is desired to connect such oversized exhaust pipes to the exhaust ports in the normal cylinder head, it has been found that when flanges are connected to the inlet ends of said exhaust pipes, the walls of said inlet ends of the exhaust pipes interfere with and frequently overlie at least part of the threaded holes by which the normal manifold is connected to the cylinder head of the engine. This situation presents serious problems with respect to providing means by which such oversized exhaust pipes may be connected to the cylinder head of a more or less conventional internal combustion engine. Various types of yokes and clamps have been resorted to for purposes of attempting to secure oversized exhaust pipes to the exhaust ports of a cylinder head of an internal combustion engine but, in general, these expedients ha ve not been very successful.

SUMMARY or THE INVENTION It is the principal object of the present invention to provide a relatively simple adaptor plate which has exhaust passages therein aligned with the exhaust ports in the cylinder head of an internal combustion engine and countersunk holes are formed in said adaptor plate adjacent the peripheries of the exhaust passages therein for the reception of large bevel-headed screws which are adapted to be threaded into the conventional threaded holes in the head of the engine adjacent opposite sides of the exhaust ports therein to provide auxiliary connecting means to obviate the need for drilling and tapping holes directly in the cylinder head of the internal combustion engine, said adaptor plate also having additional threaded holes formed therein at greater radial distances from the peripheries of the exhaust passages in said plate, said additional threaded holes being for purposes of receiving screws to secure to the adaptor plate a header flange to which the oversized exhaust pipes are fixedly connected.

It is another object of the invention to provide said header flange with exhaust holes which are adapted to be axially aligned with the exhaust passages in the adaptor plate but said exhaust holes in the header flange being of a larger diameter in order to provide means to permit the expansion of exhaust gases prior to the immediate discharge thereof into the oversized exhaust pipes, the inlet ends of said exhaust pipes being affixed by welding or brazing to the peripheries of said exhaust holes and the additional bolt-receiving holes in said header flange being disposed at circumferentially spaced relationship relative to the countersunk holes in said adaptor plate, the outer ends of the bevel-headed screws which are received in said countersunk holes of said adaptor plate being no more than substantially flush with the outer surface of said adaptor plate when connected to the head of an engine.

Details of the foregoing objects and of the invention, as well as other objects thereof, are set forth in the following specification and illustrated in the accompanying drawing comprising a part thereof.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an exemplary side elevation of a conventional cylinder head of an internal combustion engine illustrating a set of conventional exhaust ports in one side of said head.

FIG. 2 is a partially fragmentary side elevation of an exemplary set of oversize exhaust pipes connected to a header flange adapted to be connected to the cylinder head of an engine such as shown in FIG. 1

FIG. 3 is a fragmentary front elevation of one side of a cylinder head to which the oversize exhaust pipes illustrated in FIG. 2 are connected by means of an adaptor plate embodying the principles of the present invention, the scale of FIG. 3 being larger than that employed in the preceding figures.

FIG. 4 is an exemplary elevation of one of the conventional exhaust ports shown on the cylinder head in FIG. 1 but illustrated on a larger scale than employed in FIG. 1 and showing, in dotted lines, the outline of an exemplary inlet end of an oversize exhaust pipe to illustrate a typical relationship of the same to the threaded holes by which a conventional manifold is connected to the cylinder head of an internal combustion engine.

FIG. 5 is a plan view of an exemplary adaptor plate comprising the principal feature of the present invention.

FIG. 6 is a plan view of a header flange adapted to be connected to the adaptor plate shown in FIG. 5 and to which oversize exhaust pipes are connected as shown in FIGS. 2 and 3.

DETAILED DESCRIPTION For purposes of orienting the present invention with a practical illustration of its application, attention is directed to FIG. 1 in which there is illustrated a side elevation of a conventional cylinder head of an internal combustion engine. The head 10 is a casting inwhich a plurality of exhaust ports 12 have been formed. It will be seen that the ports are arranged with a pair of closely related ports in the center and an additional pair of ports 12 respectively disposed adjacent the opposite ends of the head 10. The particular cylinder head which is illustrated in FIG. 1 may comprise one side of a V-block engine, in which will be understood that there will be a similar head on the opposite side of the engine. However, in the event the engine is a four cylinder engine, the head 10 will be a single cylinder head mounted on top of an in-line cylinder block.

It also will be seen from FIG. 1 that a plurality of valves 14 are provided for the cylinders, there being a pair of such valves for each cylinder, it being understood, by means of example only, that there will be four cylinders serviced by the head 10. Each valve stem also is surrounded by a conventional valve spring 16.

The casting comprising the cylinder head also includes a plurality of bosses 18 which are integrally cast with the head 10 and are provided with perpendicular bores 20 which receive clamping bolts by which the head 10 is secured to the engine block, not shown. The cylinder head 10 also is provided with a plurality of threaded bores 22 into which conventional spark plugs 24 are threaded at an angle.

The cylinder head casting 10 also is suitably shaped to provide a plurality of machined flat facings 26 which surround each of the ports 12, all of said facings 26 preferably being in a substantially common flat plane, in accordance with conventional practice. Also, each of said facings 26 have lateral extensions at opposite sides thereof which contain threaded holes 28 that receive suitable clamping bolts, not shown, by which an exhaust manifold of conventional type is clamped securely against the machined flat facings 26, with suitable gaskets intervening therebetween, if desired.

For purposes of providing certain types of internal combustion engines with greater power to produce higher speeds for a vehicle, and particularly in regard to the operation of so-called racing cars or hot rod" cars, there is an extensive tendency at present to provide exhaust pipes having greater transverse cross sections or diameters than is afforded by conventional manifolds and exhaust pipes. In a conventional engine, there usually is a single exhaust pipe and at most, a pair of exhaust pipes when a V-type engine is used. A single manifold collects all of the exhaust gases from one bank of cylinders and discharges them into a single exhaust manifold connected to an exhaust pipe. In contrast to this, in high speed cars, such as racing cars, it is desirable to have a separate exhaust pipe for each cylinder. In addition, it is preferred that the cross-sectional areas of said individual exhaust pipes be of larger diameter than conventional manifold ports or exhaust pipes in order that the exhausting gases may pass more rapidly from the cylinder head and thus not impede the speed of the engine.

For purposes of illustrating the preferred objectives of the present invention, attention is directed to FIG. 4 in which it will be seen that there is illustrated, on a larger scale than the other figures in the drawing, a single conventional exhaust port 12 and the exemplary machined flat facing 26 surrounding the same, together with the threaded holes 28 by which a conventional manifold is connected thereto. In dotted lines, a pair of concentric circles are shown to illustrate diagrammatically the diameter of a preferred oversize exhaust pipe 30. If it were attempted to provide a flange on the inlet end of such oversize exhaust pipe 30, it will be seen that it would be at least difficult if not impossible to utilize the threaded holes 28 for purposes of securing such flange to the flat facings 26 of the cylinder head 10. Therefore, to solve the problem of attaching larger diameter exhaust pipes 30 to the facings 26 of the conventional cylinder head 10, the present invention provides adaptor means, details of which are as follows:

The principal feature of the present invention comprises an adaptor plate 32 which is shown in plan view in FIG. 5. Said plate preferably is made from sheet steel of uniform thickness of approximately one-fourth inch. The plate 32 is provided with a pattern of a plurality of exhaust passages 34 which are arranged to be aligned with the exhaust ports 12 in the cylinder head 10 when the adaptor plate 32 is connected thereto, preferably with the use of an appropriate gasket, not shown. The diameter of the passages 32 preferably is at least equal to the diameter of the exhaust ports 12 and preferably may be slightly larger than that of the exhaust ports 12. The plate 32 also is provided with a plurality of countersunk holes 36 which, when the plate 32 is connected to the cylinder head 10, are coaxial with the threaded holes 28.

The term countersunk is intended to mean a hole having a conical recess at the outer end thereof for purposes of receiving bevel-headed screw 38. Such a screw is shown in exemplary manner in FIG. 3, in phantom. It will be understood that the threads of the screws 38 are such as to be complementary to the threads of holes 28. Particularly from FIG. 5, it will be seen that the outer periphery of the conical outer ends of the countersunk holes 36 are relatively large, whereby a corresponding size of bevel-headed screw 38 will be received in such countersunk holes and thereby provide adequate means to secure the adaptor plate 32 very firmly against the machined flat facings 26 of the cylinder head 10, with an intervening gasket, not shown, therebetween.

The principal purpose of the adaptor plate 32 is to provide additional means to support and contain threaded holes 40 to serve, in effect, as a substitute-for the threaded holes 28 in the conventional cylinder head 10. However, the principal objective of providing the holes 40 in the adaptor plate 32 is to dispose said holes adjacent the exhaust passages 34 but radially spaced therefrom an adequate distance to provide an effective purchase for the clamping bolts which are to be received within the threaded holes 40 for purposes to be described. Further, it is preferred that the threaded holes 40 be spaced at least circumferentially with respect to the exhaust passages 40 so as not to interfere with the countersunk holes 36.

By referring to FIG. 5, it will be seen that the foregoing objective has been very effectively achieved by providing the adaptor plate 32 with a suitable shape that will not interfere with the spark plugs 24 or the bosses 20, but nevertheless will provide an appropriate area within which the threaded holes 40 may be provided in a manner so as to not interfere with the countersunk holes 36 and yet be sufficiently close to the periphery of the exhaust passages 34 that effective clamping of a header flange thereto may be achieved, in conjunction with a conventional type of gasket.

Referring to FIGS. 2, 3 and 6, it will be seen that the exhaust pipes 30 of larger diameter than exhaust ports 12 are connected at their inlet ends to a header flange 42, a suitable preferred shape of which is illustrated in plan view in FIGS. 2 and 6. In FIG. 6, the outlines of the exhaust pipes 30 of larger diameter are indicated by broken circular lines in order to simplify the view. Said exhaust pipes are illustrated in FIG. 6 as being aligned with exhaust holes 44 which are formed in the header flange 42, said holes being aligned with the exhaust passages 34 in the adaptor plate 32 as well as with the exhaust ports 12 in the cylinder head 10 when the adaptor plate 32 and a header flange 42 are connected respectively to the cylinder head 10 and the adaptor plate 32. Also, it is preferred that the exhaust holes 40 be of a still larger diameter than the exhaust passages 44 but said diameter nevertheless being commensurate with the diameter of the oversize or larger diameter exhaust pipes 30 which are required in order to provide suitable increase in speed for the vehicle upon which the assembly of larger exhaust pipes 30 are mounted.

The header flange 42 is also provided with boltreceiving holes 46 which are adapted to be coaxially aligned with the threaded holes 40 in the adaptor plate 32 when the header flange 42 is mounted adjacent the adaptor plate 32 and, as indicated above, a suitable gasket normally is mounted between the two in accordance with conventional practice relative to mount ing manifolds and exhaust pipes upon cylinder heads of engines. The bolt-receiving holes 46 receive headed bolts 48, for example, one exemplary illustration of which is illustrated in FIG. 3. Particularly as shown in FIG. 2, the bolt-receiving holes 46 will not interfere with the exhaust pipes 30. In addition, especially in regard to FIG. 6, it will be seen that the holes 46 are disposed at pre-determined circumferential locations relative to the exhaust holes 40 in such manner that even clamping pressure will be provided when the bolts 48 are clamped securely against the header flange 42 in order to secure the same in tightly clamped relationship against the adaptor plate 32 which, in turn, securely is clamped against the machined flat facings 26 of the cylinder head 10, with suitable gaskets, not shown, therebetween.

From the foregoing it will be seen that the present invention provides a highly effective means for mounting exhaust pipes of a larger diameter than the conventional exhaust ports of a cylinder head in firmly clamped relationship relative to said exhaust ports and providing anindividual exhaust pipe for each port by employing the conventional threaded holes adjacent the exhaust ports for purposes of effectively securing an adaptor plate against the cylinder head of the engine and the adaptor plate being provided with threaded holes by which clamping bolts may be employed to secure a header flange on a set of oversized exhaust pipes in firmly clamped relationship with the adaptor plate. Such adaptor plate is of simple and relatively inexpensive construction but also is rugged and durable and capable of long life even under rugged performance conditions.

While the invention has been described and illustrated in its preferred embodiments, it should be understood that the invention is not to be limited to the precise details herein illustrated and described since the same may be carried out in other ways falling within the scope of the invention as illustrated and described.

We claim:

1. An adaptor to connect an exhaust manifold having oversize exhaust pipes to the exhaust ports of a cylinder head of an internal combustion engine having conventional exhaust ports and threaded screw holes adjacent the peripheries of said ports, said adaptor comprising a plate having exhaust passages therethrough adapted to be aligned with said exhaust ports of said head, countersunk holes formed in said plate adjacent the perimeters of said exhaust passages and adapted to receive bevel-headed screws to secure said plate to said head by said screws en aging the conventional threaded screw holes in said ock, and sald plate being provided with threaded holes at radially spaced locations relative to said exhaust passages and adapted to receive headed bolts by which a headed flange for oversize exhaust pipes may be connected to said adaptor plate for alignment of such oversize exhaust pipes with the exhaust ports of said head.

2. The adaptor according to claim 1 in which said threaded holes are each spaced radially from the peripheries of said exhaust passages a greater distance than said countersunk holes therein are spaced from said peripheries of said passages.

3. The adaptor according to claim 1 in which a pair of said exhaust passages are adjacent each other midway between the ends of said adaptor plate and two more of said passages respectively are adjacent opposite ends of said adaptor plate, a pair of said countersunk holes respectively being adjacent the opposite sides of each of said outermost exhaust passages and said midway pair of passages and said threaded holes being circumferentially spaced from said countersunk holes relative to the axis of said exhaust passages.

4. The adaptor according to claim 3 in which a pair of said threaded holes are formed at diametrically opposite locations relative to each of said outermost passages and three of said threaded holes are located at geometrically even positions circumferentially around said midway pair of passages.

5. The adaptor according to claim 1 in combination with a header flange having the inlet ends of oversize exhaust pipes affixed thereto, said header flange having exhaust holes therein in coaxial alignment with the exhaust passages in said adaptor plate when connected thereto, said exhaust holes being larger in diameter than said exhaust passages in said adaptor plate and said inlet ends of said exhaust pipes being welded to said header flange adjacent the peripheries of said exhaust holes therein, and connecting screws extending through holes in said header flange in alignment with said threaded holes in said adaptor plate and threaded into said holes to connect said header flange to said adaptor plate. 

1. An adaptor to connect an exhaust manifold having oversize exhaust pipes to the exhaust ports of a cylinder head of an internal combustion engine having conventional exhaust ports and threaded screw holes adjacent the peripheries of said ports, said adaptor comprising a plate having exhaust passages therethrough adapted to be aligned with said exhaust ports of said head, countersunk holes formed in said plate adjacent the perimeters of said exhaust passages and adapted to receive bevel-headed screws to secure said plate to said head by said screws engaging the conventional threaded screw holes in said block, and said plate being provided with threaded holes at radially spaced locations relative to said exhaust passages and adapted to receive headed bolts by which a headed flange for oversize exhaust pipes may be connected to said adaptor plate for alignment of such oversize exhaust pipes with the exhaust ports of said head.
 1. An adaptor to connect an exhaust manifold having oversize exhaust pipes to the exhaust ports of a cylinder head of an internal combustion engine having conventional exhaust ports and threaded screw holes adjacent the peripheries of said ports, said adaptor comprising a plate having exhaust passages therethrough adapted to be aligned with said exhaust ports of said head, countersunk holes formed in said plate adjacent the perimeters of said exhaust passages and adapted to receive bevel-headed screws to secure said plate to said head by said screws engaging the conventional threaded screw holes in said block, and said plate being provided with threaded holes at radially spaced locations relative to said exhaust passages and adapted to receive headed bolts by which a headed flange for oversize exhaust pipes may be connected to said adaptor plate for alignment of such oversize exhaust pipes with the exhaust ports of said head.
 2. The adaptor according to claim 1 in which said threaded holes are each spaced radially from the peripheries of said exhaust passages a greater distance than said countersunk holes therein are spaced from said peripheries of said passages.
 3. The adaptor according to claim 1 in which a pair of said exhaust passages are adjacent each other midway between the ends of said adaptor plate and two more of said passages respectively are adjacent opposite ends of said adaptor plate, a pair of said countersunk holes respectively being adjacent the opposite sides of each of said outermost exhaust passages and said midway pair of passages and said threaded holes being circumferentially spaced from said countersunk holes relative to the axis of said exhaust passages.
 4. The adaptor according to claim 3 in which a pair of said threaded holes are formed at diametrically opposite locations relative to each of said outermost passages and three of said threaded holes are located at geometrically even positions circumferentially around said midway pair of passages. 